Tunnel Tabbing Suggestions?

[helluvaboater]

I ended up using window glass for the flat spots for the rudder and strut. I used oil based clay to make a radius/slant around the flat spots. I coated the mold with 3 coats of PVA (on top of the ton of mold release wax on there). Last night, we filled the crack with "peanut butter" and laid a single layer of 1.5oz mat. The mat measured 36x80" and went up the stringers 3 inches. I tapered the edges of the mat by ripping 1-inch off. I had to cut slits so the mat would conform around the shape of the tunnel itself and also the flat spots.

I now have 1 single layer of 1.5oz mat. We were afraid to do more out of fear of getting bubbles. There are NO BUBBLES in this layup.

Just waiting for the vinyl ester resin to cure until so I can sand it and keep going.

There is still a small valley where the tunnel meets the hull. I was thinking a bout laying in 1-inch strips of mat in all the valleys to smooth everything out more before adding more big layers.

I am going to start alternating in layers of 18-oz woven roving after every layer of mat soon.

How would you guys lay the next layers of glass?

I am using 1.5oz mat and 18oz roving. Obviously, I will be alternating in in reinforcement layers for the flat rudder/strut areas every few "big" layers of glass I do. I am assuming those layers should be staggered in size in order to not create high ridges, starting with the largest pieces first. How thick for the rudder/strut areas? I am planning to float in stainless backing plates for the rudder and strut. How thick?

 

[helluvaboater]

A little further along. Tunnel thickness is now 4 layers:

1.5oz mat
1.5oz mat
18oz roving
1.5oz mat

I also put an extra layer of mat and roving over the rudder/strut areas to make these areas thicker. The layer sheets all measure 38 x 80 in. The rudder/strut areas measure 36 x 20 or so.

I had a custom strut made.

My question is:

What's the best way to prep the cured glass for additional layers?

I mean, I know how to prep fiberglass. But for a MAXIMUM bond using VE resin on a cured laminate? I was thinking sand it all clean with 36 grit, rough it up with 16 grit makita grinder, then a HEAVY acetone wipe?

I know I should start with mat and end with mat for the best bond, but is it OK to do...

mat
roving
roving
mat
???

Or does there have to be mat between EVERY layer of roving. Can you ever do roving/roving?